Conventional cable tv systems deliver video data from a distribution company through a cable to a number of monitors of viewers. Although nowadays many programs are distributed through many channels by each cable tv company, the user or viewer has to wait until the desired program is started and transmitted through a selected channel.
Recently, also interactive video systems have been proposed. in such interactive video system a viewer can chose a desired movie to be displayed on a monitor. In such video-on-demand system a direct connection to the monitor or end device of a user is established, whereafter a demanded movie can be viewed by the end user.
In this known system it is however virtually impossible to upscale the system after it has been established e.g. at a distribution company. When the number of members for such a system increases ad the number of demanded videos is increased, a new interactive video system has to be built.
The present invention provides a storage medium unit, comprising:
storage means for storing information data;
table means for memorizing data which represent a relation between routing information and said information data;
memory means for storing program data for controlling the operation of the storage medium unit;
control means for controlling the storage means, the table means and the memory means according to the program data; and
at least one interface for transmitting the information data with the routing information for such information data in the form of a packet to routing means.
The storage medium unit according to the present invention makes it possible to upscale the system by connecting one or more additional storage medium units to the system. The interface provides for standardization of the information data and routing information in the form of one or more packets, so that the storage means of the storage medium unit according to the present invention may comprise all sorts of storage mediums, such as one or more hard discs, one or more magnetical optical discs, video tapes and/or other.
Preferably said program data are down-loaded from the interactive system, so that only a minimum amount of software has to be included in the storage medium unit.
Preferably said information data and video and/or audio data although the present invention is not limited to this application. The storage medium unit according to the present invention may also comprise application for video games, library function and databanks, although first promising application fields relates to video-on-demand services.
Preferably said interface comprises an ATM interface. The basics and standards of ATM (Asynchronous Transfer Mode) are laid down in recommendations I.150 and I.327 as published in March 1993 by the International Telecommunication Union). ATM is generally used for addressing a specific packet-oriented transfer mode which uses asynchronous time division multiplexing techniques. The multiplexed information flow is organized into blocks of fixed size called cells. A cell consists of an information filed and a header. The primary role of the header is to identify cells belonging to the same virtual channel within the asynchronous time division multiplex.
Preferably the storage medium unit according to the present invention provides for still mode operation, fast forward mode operation, reverse mode operation and mosaic mode operation as in a video cassette recorder (VCR).
The present invention also provides and information service system, comprising:
one or more storage medium units, one or more end devices; and
at least one ATM switch for connecting the storage medium unit to the end device, wherein said storage medium unit comprises:
storage means for storing information data;
table means for memorizing data which represent a relation between routing information and said information data;
memory means for memorizing program data for controlling operation of the storage medium unit;
control means for controlling the storage means, the table means and the memory means according to the program data and for outputting control signals to the end device; and
an ATM interface for transmitting said information with the routing information and the control signal in the form of one or more ATM packets to the ATM switch and for receiving the program data for operation of the storage medium unit in the form of ATM packets from the ATM switch.